Looking to upgrade front and rear brakes that fit stock wheels any suggestions?
03-24-2001, 07:09 AM
#3
New Member
Join Date: May 2000
Posts: 224
Likes: 0
Received 0 Likes
on
0 Posts
I installed new pads and cyro-treated and slotted rotors
<center><img src="http://www.digitalgarage.net/s4/wheel_close_up.jpg"></center><p>It was fairly cheap, no breaking of the lines in the brake system and the car looks better too.
cryogenically treating the rotors reportedly makes them around 3 times as strong, although I have not had them long enough to prove this. The rotors do have around 1000 miles on them and you can still see the surface finishing marks on the rotor, so they seem to be harder than the factory rotors that looked pretty bad after 6000 miles and one track event.
So far, I am really happy with it.
frozenrotors.com is who sold me the rotors and the carbontech pads if your interested. I think it was 1200 for 4 rotors and front pads.
cryogenically treating the rotors reportedly makes them around 3 times as strong, although I have not had them long enough to prove this. The rotors do have around 1000 miles on them and you can still see the surface finishing marks on the rotor, so they seem to be harder than the factory rotors that looked pretty bad after 6000 miles and one track event.
So far, I am really happy with it.
frozenrotors.com is who sold me the rotors and the carbontech pads if your interested. I think it was 1200 for 4 rotors and front pads.
03-24-2001, 08:27 AM
#5
New Member
Join Date: May 2000
Posts: 224
Likes: 0
Received 0 Likes
on
0 Posts
I wanted a 4 wheel solution, not just the fronts [more]
So it really came down to a matter of 2000 vs. 4000 for both axles to do a complete solution.
Then I started thinking about brake maintenence costs (ease of finding and replacing rotors, pads) and resale value (its harder to sell modded cars due to the abuse issues), vs. the amount of time I was going to keep the car, warranty voiding and all the other crap that goes along with doing it and just decided to clean up using the existing OEM hardware and leave well enough alone.
I track maybe 1 time a year, the tracks around here are big, so brake warping problems are not really an issue for me, so I saved myself the money for my next project car.
Then I started thinking about brake maintenence costs (ease of finding and replacing rotors, pads) and resale value (its harder to sell modded cars due to the abuse issues), vs. the amount of time I was going to keep the car, warranty voiding and all the other crap that goes along with doing it and just decided to clean up using the existing OEM hardware and leave well enough alone.
I track maybe 1 time a year, the tracks around here are big, so brake warping problems are not really an issue for me, so I saved myself the money for my next project car.
Trending Topics
03-24-2001, 10:14 AM
#8
New Member
Join Date: Jul 2000
Posts: 325
Likes: 0
Received 0 Likes
on
0 Posts
Brembo has thier own 13" kit out for the front as far as the backs your gonna need...(long)
<center><img src="http://pictureposter.audiworld.com/8259/jens_audi.t.jpg"></center><p>to use and Alcon kit probably. They're pricey (Alcon) but worth it in my opinion.
If you didn't want to get carried away, I would use Hawk Pads, they're inexpensive and work as good as the Pagids with less dust. Cryo the rotors, stianless break lines the whole way around. And most inportantly build some trick venting to the front rotors, which will help more than anything else you could do.
Remember that by racing/sports car standards the S4 is an overwieght pig. Your probably close to 4000 pounds with you and a full tank of gas.
Remember you need to focus on heat dissipation, not grip, you have plenty of grip with the stock set up and better pads will give you the illusion that you improved your brakes, which you did to some point, but your still gonna warp the rotors unless you get some cooling.
However your fundemantal misktake in the long run is keeping the stock wheel, you can make a great performance improvemnt by getting some lightwieght rims, that can accomodate a Brembo or Alcon 14" kit, that would be the right way, in other words, more rotor while reducing unsprung and rotational wieght.
If one does the math I think taking 10 pounds of each wheel is the same as adding 10-20 hp, plus it pays off in handling as well. There is a really slim chance that the new 14" Brembo and maybe the Alcon kits will fit the stock wheels, but it is gonna be close. The 13" Brembo Lotus Caliper kit you see in the pic will fit a stock s4 wheel.
Everyone is under the misconception that wheels are changes for looks, but don't realize there are alot of hidden, all be it not glamorous, performance improvement to be made with the wheels. Oh and don't forget you gonna need a real tire. Feel free to email me if you want more info.
If you didn't want to get carried away, I would use Hawk Pads, they're inexpensive and work as good as the Pagids with less dust. Cryo the rotors, stianless break lines the whole way around. And most inportantly build some trick venting to the front rotors, which will help more than anything else you could do.
Remember that by racing/sports car standards the S4 is an overwieght pig. Your probably close to 4000 pounds with you and a full tank of gas.
Remember you need to focus on heat dissipation, not grip, you have plenty of grip with the stock set up and better pads will give you the illusion that you improved your brakes, which you did to some point, but your still gonna warp the rotors unless you get some cooling.
However your fundemantal misktake in the long run is keeping the stock wheel, you can make a great performance improvemnt by getting some lightwieght rims, that can accomodate a Brembo or Alcon 14" kit, that would be the right way, in other words, more rotor while reducing unsprung and rotational wieght.
If one does the math I think taking 10 pounds of each wheel is the same as adding 10-20 hp, plus it pays off in handling as well. There is a really slim chance that the new 14" Brembo and maybe the Alcon kits will fit the stock wheels, but it is gonna be close. The 13" Brembo Lotus Caliper kit you see in the pic will fit a stock s4 wheel.
Everyone is under the misconception that wheels are changes for looks, but don't realize there are alot of hidden, all be it not glamorous, performance improvement to be made with the wheels. Oh and don't forget you gonna need a real tire. Feel free to email me if you want more info.
03-24-2001, 11:25 AM
#10
AudiWorld Super User
Join Date: Nov 2000
Posts: 4,219
Likes: 0
Received 0 Likes
on
0 Posts
You asked for it, so here goes. : -)
The best mechanic I have ever come across, my best friend and racing buddy, happens to also have a PhD in physics. We kept shaking our heads about the outrageous promotional claims of cryogenically treated brakes. Neither of us could find any basis in physics for it, and neither could several metallurgists we spoke to.
Eventually, the opportunity came for my friend to challenge the promoter of this black art in connection with some accident investigation. He spoke with the man repeatedly, requested all supporting data and literature he could get, and came up with exactly nothing, except that the guy honestly seemed to believe in what he was doing. And that was to immerse brake disks in liquid nitrogen for a while and then allow them to warm up slowly. This was supposed to cause molecular realignment into near crystalline lattices. You name it, it did it.
Along with these claims went two micro photographs that also appeared in some of the adds for these brakes. They allege to show rotor surface structure with and without cryogenic treatment. After my friend challenged the author of these pictures, HE ADMITTED that both came from the same negative but with different magnification. So much for scientific proof.
We all know that heat treating can change the properties of steel. But if that steel is then reheated until it glows bright read, it will go right back to its initial properties. Now, take a "cryogenic" brake disk and run it at the 24 Hours of Daytona where it glow cherry read near constantly for 24 hours. Do we believe that that disk will retain its alleged cryogenic molecular orientation? In fact, it will be fully annealed. Like any other rotor, its friction surface may have developed some hard spots where carbon from the pads was absorbed into the steel to form higher carbon steel (which is undesirable because of a lower coefficient of friction).
My buddy and I came to the conclusion that cryogenically treated brake discs are a brilliant promotion by a true believer that you can avoid annealing if you freeze the hell out of the discs beforehand. It does make some intuitional sense, doesn't it? : -)
Disclaimer: The above refers only to brake disks. I know nothing about possible other cryogenic treatments of materials that are not then heated to extreme temperatures.
Eventually, the opportunity came for my friend to challenge the promoter of this black art in connection with some accident investigation. He spoke with the man repeatedly, requested all supporting data and literature he could get, and came up with exactly nothing, except that the guy honestly seemed to believe in what he was doing. And that was to immerse brake disks in liquid nitrogen for a while and then allow them to warm up slowly. This was supposed to cause molecular realignment into near crystalline lattices. You name it, it did it.
Along with these claims went two micro photographs that also appeared in some of the adds for these brakes. They allege to show rotor surface structure with and without cryogenic treatment. After my friend challenged the author of these pictures, HE ADMITTED that both came from the same negative but with different magnification. So much for scientific proof.
We all know that heat treating can change the properties of steel. But if that steel is then reheated until it glows bright read, it will go right back to its initial properties. Now, take a "cryogenic" brake disk and run it at the 24 Hours of Daytona where it glow cherry read near constantly for 24 hours. Do we believe that that disk will retain its alleged cryogenic molecular orientation? In fact, it will be fully annealed. Like any other rotor, its friction surface may have developed some hard spots where carbon from the pads was absorbed into the steel to form higher carbon steel (which is undesirable because of a lower coefficient of friction).
My buddy and I came to the conclusion that cryogenically treated brake discs are a brilliant promotion by a true believer that you can avoid annealing if you freeze the hell out of the discs beforehand. It does make some intuitional sense, doesn't it? : -)
Disclaimer: The above refers only to brake disks. I know nothing about possible other cryogenic treatments of materials that are not then heated to extreme temperatures.
Thread
Thread Starter
Forum
Replies
Last Post
fatty711
A4 (B5 Platform) Discussion
7
02-25-2004 10:43 AM
hoTTub
TT (Mk1) Discussion
36
08-10-2001 05:21 AM